AR 102 EXPLORE SCIENTIFIC REFRACTOR REVIEW.

AR 102 Refractor review.

By Haseeb Modi.

AR 102 the Scope:

Astronomy is a hobby that keeps growing while making you feel younger. Sounds strange but this is a fact.
Consider this. The average age of an Astronomer is around 35 yrs, give or take a few. That would mean, amateur astronomers, ranging from ages 12 - 70 yrs. I know for certain there are amateur astronomers who are well within striking distance of a century.
Now coming to the point, owning a Dobsonian and SCT is fun and continues to be so. However, after reading so much about how a Refractor provides wide-field, rich contrasty views, the insatiable appetite for yet another fling at an instrument was on the cards.
Fortunately, I had a cousin of mine coming down from the States and he was kind enough to accept my request and get me an achromat, i.e., Explore Scientific's AR 102.  First off, this was the cheapest option I could see, and second, Explore Scientific has a good reputation. Besides, I wanted to see what exactly were these wide-field views of a Refractor and lastly, the saddle plate is universally adaptable.



When the scope arrived, I found to my chagrin, the Diagonal was missing. I got this later on with my cousin's help ( I really appreciate all that he did ). The finish was white with a protruding longish dew shield. The paint was high quality and the components were sturdy. The focuser seemed quite smooth and strong enough to hold a 2" diagonal with a heavy eyepiece or camera.  The only issue I had was when the focuser got stuck by the adhesive used on the plastic markings which I had to get rid off. Minor issues aside, the feel was solid. The straight-through 8 x 50 finder was adequate for the purpose and aligning to the scope during daytime was easy enough. Some may think the Finderscope looks misaligned mounted on the scope and indeed that would be one's perception when seeing the scope in its entirety. However, it works and that's that.
The baffling is good enough and the coatings are great. The dew shield ( I always keep it extended ) helps protect the lens from the forces. There are six small collimating screws but the scope came well collimated out of the factory and the star test showed concentric circles both inward and outward focus.



FIRST LIGHT:

This air-spaced doublet has a 663 focal length and f/6.5 focal ratio. It is relatively large with a diameter of 102mm or 4". The highest useful magnification is stated at 220X. I never had a chance to go that high but I did push the scope up to 200X by using an ES 6.7mm 82 degrees eyepiece with a Barlow inserted. Saturn at 200X was completely in focus. A fine focus ring helps in making micro corrections.
Normal views through this Achromat are quite pleasing with only the brightest of objects showing hints of CA or Chromatic Aberration or purple fringing.
What is surprising is the fact that even in extremely light polluted conditions, viewing from within a large city, I was able to see M 31, M 13, M 57, and other Globular clusters. Only faint galaxies or galaxies with less surface brightness would be difficult to find but that is something even an 8" Dobsonian may find difficult to obtain from light-polluted cities. Of course, even an 80mm Refractor will give you pristine views of fainter galaxies provided one takes a trip to the outskirts or to areas with less light pollution.
The Moon and Planets however are excellent to look at. What really stands out in all its beauty viewing from this Achromat Refractor are the Open clusters. Being in the Southern region, we are blessed with the Sagittarius area which forms the bulge of our Milky Way and thousands of stars are visible through the scope even from light-polluted cities. Just ensure the nights are clear with little to no clouds and try to shield your eyes and scope from stray light or neighbors lights.

ASTROPHOTOGRAPHY:

Now an Achromat or a normal doublet is not the ideal choice for imaging. But one has to make do with resources available and none better than an F/6.5 with a short focal length to try my hand at imaging some galaxies. This scope performed within expectations but the purple fringing or purple halos around brighter stars are prominent.  Here's an example:


I had to process this image vigorously to remove the "purple fringing" but could do nothing about reducing star size. In fact, this image is after using Noel Carboni's star tools and star reduction and purple halo reduction around stars. But the image is pretty and more than can be expected with minimal equipment, imaging from inside a light bowl.
Bear in mind though, there are other Doublets with Extra Dispersion or ED glass and with even 65mm aperture, which can make for excellent astrophotography equipment. Their short focal lengths and the focal ratio will help in snaring galaxies, even fainter ones. Only be prepared to take as many "light frames" or "Subs" as possible to stack them later to obtain signal-to-noise reduction as well as enough photons to bring out detail.

( Disclaimer: This review is purely based on my own reading and from my own perspective of AR 102 and I have not affiliated in any way with Explore Scientific ).
Haseeb Modi.

VIXEN BT81S-A Review

By Haseeb Modi

Vixen BT81S-A Astronomical Binoculars:

Fortunate indeed is an amateur astronomer who gets time to spend under the stars rather than sitting and watching soap operas. Even more fortunate is an amateur astronomer who has a friend who is passionate about astronomy and shares his passion with others.  I am of course referring to the ‘Passionate Astronomer’ who owns a plethora of scopes and equipment and has helped others enjoy this wonderful hobby.

If you recall, I had mentioned in my earlier review about him searching for an instrument which he would cherish. While this instrument may still yet elude him, in the interim period, a Vixen BT81S-A came into his possession.  This Japanese built bino scope is a thing of beauty. One glance and you know you have a winner.

The official specifications:

Magnesium Flouride coated, air spaced doublet design offers to dramatically reduce chromatic aberration and leave you with crisp, clear images. Optical coatings fully multi coated with BAK-4 glass and Porro Prism type. Total weight 9 lbs and..

• Focal Ratio F/5.9
• Aperture : 81mm (3.1")
• Focal length - 480mm
• Resolving Power: 1.43 arc secconds
• Features: Carry Handle, Finder Bracket
• Dimensions: 18.9" x 7.4" x 6"
• Warranty: lifetime.

Note the last part, now that is something.

The package comes in two boxes with the box containing the scope within another. Styrofoam protects all sides from bumps while transporting.

I had the opportunity to check out this binocular scope and take some pictures for the readers to see. The construction is solid as usual and the prisms have that clean, high quality look. The front 81mm objectives are even more brilliant and looking through from a light source, I could see all the way without the slightest aberration, dust speck or anything of the sort.

My friend had a Garrett 5000 series head ready on hand to attach at the bottom plate and a 058B Manfrotto heavy tripod. While I have not yet taken a look through, the owner did and according to him, the downgrade in aperture from 100mm to 81mm has not really impacted the views much. In fact these high quality objectives have provided him with good contrast and pinpoint stars with hardly noticeable chromatic aberrations.

I like the Helical focusers, they look well built and smooth to operate. I would assume from the initial observation made by its owner, the collimation is bang on with no fingernail leakage.  I am still new to binocular scopes so would rely on my buddy to tell me in case to the contrary. To me however, this package reeks of all round quality and a keeper for those already accustomed to bino-viewing.

Haseeb Modi.

Polar Alignment for Southern dwellers.

This is the procedure I adopt for an equatorial mount. I have a CG-5:

1. Place Tripod / Mount / Weights.
2. Ensure "Alignment Peg" is roughly pointed towards Polaris.
3. Sight through the Borehole to check if Polaris is visible and centered.
4. Place Scope on saddle plate. Insert Diagonal and eyepiece.
5. Check 'balance' ( very important ) with 4 in place and adjust weight accordingly till the balance is achieved.
6. Make sure Mount is connected to A/C outlet or Powerpack. Switch on mount.
7. Ensure your Latitude scale is as per your location, i.e, N =. Enter your Latitude and Longitude in the remote. ( If you live in extreme Southerly region, you can use Octantis as your South star ).
8. Enter date / time / Zone into your remote. ( Note: This may be slightly different to other brands or make ).
9. Ensure Finderscope is aligned correctly with the eyepiece of your main scope.
10. Start two star alignment. The first or even second time, the stars will not be in the center of your finderscope. Don't worry, just adjust with controller till you have the star centered in both your finderscope and eyepiece.
11. Do a four star calibration. This will basically ensure objects within your eyepiece do not move for hours and will even provide for steady imaging of Planets / Moon though DSO's may require more stringent polar alignment routine.
12. Post back your viewing session or comment on how you go about your polar alignment routine with your set up. Enjoy.

Polar Alignment for Astrophotography:

There are couple of methods, i.e., Drift Alignment and Iterative Alignment. While I found Iterative Alignment provides good results, I am yet to do a drift alignment. However, this alignment procedure that I follow has given me steady results without Auto guiding.  This is not to say Auto guiding is not necessary. For those living under dark skies or have access to dark skies, a good auto guider can be invaluable, helping you image as long as you like.

For this method of mine however, I am limited by severe city light pollution and therefore, even if I had an auto guider, my images would look washed out after two minutes. No point unless I travel to the outskirts.

So coming back to the subject for a simple Polar Alignment for astrophotography, I follow these steps AFTER completing above mentioned points:-

1.  Look for a star like Antares or Capella. Stars very close to the poles will be instantly rejected by the controller so chose your star based on your current sky map.

2.  Enter the name of the chosen Star into your controller, press ENTER and wait for the scope to slew towards this Star. Invariably, even though you got the calibration stars done in the earlier steps and while for visual that is more than adequate, you will find the Polar alignment routine a bit more stringent. The star in question will not be exactly in the center of your eyepiece. More likely towards the edges.

3.  Scroll down on your controller to "Polar Alignment" and "Align Mount". Press ENTER. Follow instructions to center the star in the Finderscope first and then in your eyepiece. ( I just center it in the eyepiece and press ENTER and then ALIGN ). Most folks tend to use high magnifications for getting the star properly centered or even an illuminated reticle.

4.  After you finished centering in both your Finderscope and Eyepiece, press ENTER. The Scope will slew a bit away from the chosen star. In some cases, you may not even find this star in you Finderscope let alone the eyepiece. Not to worry.

5.  The Controller will now ask you to calibrate the Mount with the Alt / Az knobs manually. Keep your Controller aside. Look through the Finderscope and see if you can spot the Star. Usually it will be there and if your initial alignment was good, the star may just be a wee bit outside the eyepiece. Use the adjustment screws to slew the star towards the center of your Finderscope. Look through the eyepiece and see if the Star is now visible. Try to center it in the middle as much as possible. If the screws do not allow you to center the star, you must then use the hinge wing screw on the back of your mount to "raise or lower" the mount. Make small adjustments till the star is in a position, whereby simply turning the Alt / Az screws should now bring the star towards the center of your eyepiece.

Press ENTER and see if your display reads 00.00 / 00.00.  All done. You can now image for up to a minute with a Refractor or up to 3 minute with a Lens piggy backed. Probably more but I never tried due to severe light pollution. But that hasn't put me off Astrophotography. I still continue to capture photons in my camera and feel happy to see the results, however amateurish they may look. But the joy of having achieved something which the eye cannot see in itself is a simple enough reason to enjoy Astrophotography.

Haseeb Modi.

C6-SGT review.

C6-SGT: REVIEW:  



The insatiable appetite for astronomy never ends.  Having started my journey with an 8” Dobsonian,  a journey which both my family and I enjoy endlessly and will continue to do so for the rest of our lives, the need to bring in something different and try to further enhance this wonderful hobby never escaped me. This idea bore fruit after three months of waiting and saving, to finally set my eyes on a brand new C6-SGT from Celestron.

PACKAGE CONTENTS: ( Three boxes ).

1.    Tripod.
2.    Mount head.
3.    Spreader tray.
4.    Nexstar Remote.
5.    E-Lux 25mm Celestron.
6.    C6 OTA with Starbright XLT coatings.
7.    Diagonal – 1.25”.
8.    Two instruction manuals.
9.    The Sky Planetarium CD.
10.    DC Car Adapter.
11.    Finderscope. ( note: Bracket for the finderscope comes attached ).
12.    Caps for all, i.e., eyepiece / diagonal / OTA.
13.    Weights – 11 lbs.


CG-5: THE MOUNT:

My first introduction to a German Equatorial Mount.  There were moments of dread, fearing the worst on the trails of a complicated EQ mount. However, once my family and I set eyes on the Mount itself,  all was forgotten.  My two children quickly made a check list while my wife and I started to assemble the Tripod.  With directions from my children, the assembling of the CG-5 was done clinically and efficiently.  It took us under 30 minutes.

Initially, I extended the legs fully and to my surprise, the mount was a good 6’.  The legs are a beefy 2” stainless steel and once the legs were collapsed, the CG-5 looked  quite solid.  I would daresay, this mount would easily hold an 8” Reflector or a 6” Refractor.  In our case however,  the mount was more than adequate for the C6 OTA. At the back of my mind, I had already begun calculating the accumulated weights of a DSLR at Prime Focus or heavy Eyepieces like the Baader Hyperion 8mm or an Explore Scientific 11mm coupled with a Televue Barlow.  Newcomers like me,  interested in casual astrophotography, would do well to keep this at the back of their mind, i.e., accumulated weight.

In my estimate, the mount with Tripod and weights should be near to 19 kgs.  If one needs to carry this singly, the head could be separated and the Tripod legs closed for easy transport.

First timers who need to deal with an EQ mount should not feel overwhelmed, but at the same time, read the “Manual” provided thoroughly and practice both alignment as well as get acclimatized by knowing exactly where ‘on the field must use’ items like Clutches / Declination axis etc., are positioned so that your session goes smoothly.

One important point to note here is, the CG-5 is designed with a 30-60 degree Latitude. What this basically means is that astronomers using this in the Southern Hemisphere or right on or near to the North Pole would have some limitations for accurate Polar Aligning. There are workarounds though in locations which are somewhere less than 30 degree Latitude.  In this regard, I wish to thank both TEL and ARTIC EDDIE of Cloudy Nights for their valuable inputs at the Celestron forums.

The mount comes factory assembled with the “Alignment Peg”  between the Tripod legs.  NOT on the North Leg as one would think.  In my case, this worked perfectly as I didn’t require to relocate the Alignment Peg.  All I did was to loosen two bolts and remove the bracket from the front along with the screw.  This enabled me to lower the mount scale by another   13 degrees,  thus giving me  a 17 degree latitude.  My Latitude is N 13, therefore I would require to slightly adjust the South Leg by extending it and attaching a weight to avoid tipping over.  ( Hope Celestron  realize their clientele is not limited to just areas between Latitude 30-60 degrees, but worldwide ).

For our friends in the Southern Hemisphere, the star Octantis can be used for alignment though there are many who are adept in finding solutions with wedges and custom machined parts.  I am not one of them though.




NEXSTAR REMOTE:

Initially worked well during mock alignment, when suddenly I had a scare when the message “Transmit Data” appeared.  A few posts later and thanks to members at Cloudy Nights again, I was able to overcome this. It was a simple matter of obtaining an RS 232 cable with an Adapter to suit your OS and by finding the requisite ‘Port’, connect to Celestron’s website and download the latest firmware. It worked and so far the Remote is doing fine. I also upgraded the Firmware for Motor Control so that both the Remote as well as the motors are in tune with each other.

Slewing to an object while doing a mock alignment seemed quite smooth with a bit of whining noise which is to be expected and not something which should wake up your neighbours.  Later on I reduced the speed to 2 degree which helped lower the noise.

The LCD is clear and the buttons are well spaced out.  The red illuminated remote does not spoil your night adaptation.  Again I would suggest you thoroughly read the manual to get familiar with the various button controls, even though each one has got markings for their intended purpose.

OTA / ACCESSORIES:

The C6 looks quite modest, actually bigger than the pictures you see on the website and or in this review, but quite manageable.  Celestron is clearly marked with a sticker on top stating “Starbright XLT”.

The bracket for the Finderscope comes installed from the factory and all you need to do is insert the Finderscope and use the three screws provided to tighten and align.  Though aligning is easy, craning of the neck to view is not.  Therefore, if one wishes to upgrade, a nice little RACI would be a welcome addition.

The backside of the OTA has a protruded grey knob which is the “Focusing knob” and works well. The diagonal however is something you would want to keep aside and upgrade almost instantly.  My Baader Hyperion eyepiece could not be inserted completely and I had to leave the left side screw loose to accommodate it.  Not good.

Any good SCT  2” diagonal with 1.25” adapter or an Astrotech’s award winning  1.25” diagonal would be the immediate thing to do.  I am hopefully waiting for this to arrive soon.

The Celestron E-Lux 25mm eyepiece however fits well on this stock adapter and the eyepiece itself looks quite good with adequate eye relief and wide field of view.

The knurled ring at the back of the OTA provides for tightening or holding a focuser or camera at Prime focus.

ALIGNMENT:

Mock alignment is one thing. Going out to the field and see a sparsely star lit sky from a light polluted city dome is another.  Monsoon season coupled with a bright Moon do not help matters either. Patience wears out quickly and here’s where one must exercise diligence and determination.

A couple of nights with no rain though still partially cloudy, we took the C6-SGT for our first outing.  Our Latitude and Longitude was entered, alongwith time, date, standard time, zone 5 ( in my case ) and a two star align started.  Though the scope itself seems to point at the requisite Star, both the Finderscope and the eyepiece failed to spot it. Fine tuning with the arrow keys to center the Star/s in the Finderscope first and then the Eyepiece, yielded results somewhat okay though not perfect.

Tracking did not seem to hold up after a minute with the object slowly drifting out of view.  Once again, with the help of feedback from seasoned members and their input on trying a ‘Calibration routine”, decided to wait for a night when the cloud cover would be less or non-existent with no rain.

Yesterday was such a night.  Faith seemed to aid me as well as Polaris was visible, just above the horizon. I quickly lined up the Tripod with the Alignment Peg pointed straight at Polaris. Opened up the Polar finder caps and eyeballed Polaris.  Used the Azimuth / Altitude screws to bring it in center and then fired up the motor.

I decided a two star align followed by four star Calibration routine.  As the hand controller gives you choices in case you have trees / buildings blocking your view, I did not worry about this. Everything went smoothly and by the time I got to the third calibration star, both the Finderscope as well as the Eyepiece had the object in view.  By the fourth calibration star, things were beginning to look spot on.

FIRST LIGHT:

Hit ‘M’ on the Nexstar and entered ‘042’. Lo and behold, M 42 was dead-on.  The stars in the trapezium looked like jewels and the nebula itself appeared quite clear.  I was fearing the views between my 8” compared to this 6” would be somewhat anti-climactic. They were not and while still cannot compare to an 8”, not exactly a let- down either.  I was using a 14mm Meade 5000 super Plossl with 60 degree FoV.

Next we entered M 31 and the scope slewed right there for the great galaxy to be visible in the eyepiece. With a full Moon quite close to the vicinity, we could still see M 31, probably due to its magnitude of less than 4.00.

We then slewed back to M 42 and I decided to give Prime Focus a go. Inserted a T2i at Prime Focus and through the viewfinder, focused on Orion’s great Nebula and started testing.
Thirty seconds showed some trailing. Twenty seconds did not show much trailing, I therefore, settled on twenty five seconds.  Ten light frames later, we were astonished to see the Great Nebula’s color and profile light up the camera’s preview window. It was exhilarating and perhaps the highlight of this basic astrograph equipment.  We then slewed to a few open clusters like M 36 / M 37 and they were all bang in the center. Clouds were rolling in and we had to wrap up the session.

To add, views of Jupiter were crisp with the Barge clearly seen.  Moon was glittering to say the least with all the craters showing up with clarity. The XLT coatings do seem to live up to its name.

For all the trials and tribulations, mainly due to my location, overcoming these kind of hurdles,  adds to the excitement, especially when you pull out something which you always dreamed off.  Nothing spectacular  but at the same time, something to show and talk about.  As long as newcomers to astrophotography learn to understand the limitations of this basic set-up and are prepared  to  undertake this journey, the adventure would be both exciting and rewarding.

For more serious astrophotography, there are many add-on’s to this mount like a Radial Glider, Polar Finder scope, Auto-guiders etc.,

Clear Skies!

Disclaimer:  I am not affiliated / associated with any brand names or vendors mentioned here in this review.

Haseeb Modi.

P.S: I wish to thank all those who guided me in this process of alignment, figuring out on how to overcome my latitude scale and giving some extremely helpful tips on Polar alignment.

Please visit www.indianstronomer.net

M 42 Orion Nebula as imaged through different scopes.

Taken with an Achromat refractor, i.e., Explore Scientific AR 102 with Canon Dslr.

Orion nebula as taken through a SW100ED and Dslr.

 

 

Zhumell Z8: First light!

FIRST LIGHT ON A Z8.



( This is only a perspective from my own personal viewpoint and this review / writer is in no way affiliated or connected with Zhumell ).

To begin with, thanks to each and everyone of you who contributed towards all my questions.

Right, so my friend from U.S.A., came in today morning and carried with him a large long box.  Lugging around with this huge box itself is a severe test of friendship but my friend even went to the extent of sewing up a “leather case” for the Optical tube box using black cow finished leather.  A friend indeed.

The base material and accessories were in his suitcase as he had them opened up to carry it along more easily.  I got them in the evening, all bubble wrapped.

I did not know where to start but my children felt the best way would be to unzip the leather case and take a look inside.  What I saw made me skip a beat. The OTA was not only long, but the diameter blew me away.  Thoughts running in my mind were, “how in heaven’s am I going to carry this two flights of stairs without knocking something”?

But first, we needed to unpack each and every component and make a list of what was needed and what came as additional accessories.

Additional Accessories:

1.     Right Angle Correct Image finder scope.
2.    30mm 2” Plossl / 9mm 1.25” Plossl.
3.    Laser Collimator.
4.    Battery holder with wires connected for the rear fan.
5.    Two large bearings. ( Here I was a bit disappointed as earlier videos showed “silver bearings” whereas mine came with black knobs ).
6.    Moon filter.

Don’t want to go into details of the base assembly and what was needed as I am sure almost all of you would be aware.
The base assembly was not difficult and with the help of Zhumell’s website video, we were able to assemble without issues.

FIRST IMPRESSIONS:

As I inspected each and every piece, the only thoughts running through my mind were, “ how am I going to carry this two flights of stairs?” This worry turned into genuine concern after assembly, eyeing the huge OTA and the heavy base. ( For beginners like me, kindly note, unless you are in good shape and physique, this Z8 is going to be an issue if you don’t have an escalator or a backyard ).

However, the excitement of seeing something this big actually made my expectations soar. The build quality, material used was superb.
Collimation was a breeze and in fact, this particular piece survived the long haul from U.S. to India in extremely good shape.  Here I wish to once again add the care taken by my good American buddy.

I lifted the base assembly and though weighty, was manageable. The OTA, a little less weighty but cumbersome to hold was another affair, what with four steep turns to manuveur the long tube ( 4 ft.).

We couldn’t wait for dinner time. My children and wife were excited and so was I. At sharp 2130 hrs, with my wife’s help, sharing the burden of carrying the assembly while I carried the OTA, we set off on our first astronomic adventure. The skies were beckoning and we were keen.


FIRST LIGHT:

The terrace was empty and the skies clear. Not a hint of cloud though the “light bowl” effect of the city glow was evident. To make matters worse, a neighbor two blocks away decided to keep his outside tube light on for the night, directly below Orion.
I first set my sights on Sirius and then on Orion. I used the 30 mm Plossl. Sirius appeared to be “flat” with a black hole right in the middle and four paned.  Question: Is this something to tell me that my collimation was accurate? I remember reading somewhere if the collimation is “off”, Sirius would appear flowery.
 
The RACI ( Right Angle Correct Image ) is an excellent accompaniment though getting it to align with the eyepiece takes some doing.

The Orion Nebula appeared dim and not very bright. I started becoming a bit desperate. Was I doing something wrong? Then I loosened the bottom screw and voila! The Crayford focuser started to move up and down and the Stars changed from dim to diamonds.  From here on, I was halfway towards achieving Nirvana.  I changed the eyepiece to 9mm Plossl.

My children and wife took turns. Sirius was very bright with four sharp glitters of light streaking across from four points.  My wife was ecstatic. My children were okay. I was neutral.

Then we watched the Orion and with the knowledge of “focusing”, was able to see a nice graying cloud with four stars inside a bigger source of light. My children loved it.

My daughter wanted me to train the scope on some particular star which appeared to have hues of light. Accidentally, while trying to move down from Sirius, I hit upon a cluster of stars and immediately everyone started to gaze in awe. It was a terrific sight to behold.

My son all this time kept talking about Saturn and the time when it would hit the Zenith. There were two bright stars on my left and one more a little way more towards south east. We weren’t able to figure out which one was Saturn but in anycase, my first ideal was to get a good hold of this 8” Dob and seek out some more clarifications.
2300 hrs and we were still hunting for galaxies when we again hit upon a cluster of stars in a globular fashion which my son promptly told me was M45.  I thought this was the best time to turn my sight and try to see Saturn.

The bottom most yellow stars out of the three was a fake. The uppermost one was difficult to focus. I was tired and felt my family though happy with the sights, were definitely not jumping over the moon.   My daughter then took over and tried to focus on the middle yellowish object. She then asked me to look through the eyepiece.

Nirvana! Instant and pure nirvana. Money well spent and the advice from this forum golden. This image of what we saw will be etched in our memories forever. It was unbelievable and breathtaking. We were in awe and as if a home run was scored, in unison we started clapping.
Saturn was not only clear, it was crystal clear. We could see six moons at least and the rings were amazing. It had that two tone yellow / crimson colours and my wife remarked, “ we got our money’s worth” and that says it all on the capabilities of this wonderful 8 inch Dobsonian.

Haseeb Modi.

Please visit www.indianastronomer.net and help spread astronomy in India.

M 42 Orion nebula

     Took this image on the night of 6th February 2014 with the longest integration of 59 minutes. Half moon but sky was relatively clear.

ASTRONOMY, ASTROPHOTOGRAPHY & YOU

By Haseeb Modi

ASTRONOMY, ASTROPHOTOGRAPHY & YOU:

Astrophotography is extremely popular even for those visually interested in astronomy. However,  to own a complete unit comprising of even minimal equipment which helps track the skies for long durations of time can quickly become expensive and then some.

Amateur astronomers of all ages like to indulge in astrophotography. There are die hard viewers who only prefer visual viewing and that’s fine.  There are also those who prefer the simple classic way of observing with either an Alt / Az or Dobsonian mounts by manually slewing to objects. This involves a relatively good understanding of the skies and keeping star charts or smart apps on your Android phone to chart out the sky map for your location on the given date and time. 

I bet almost everyone right from their school days wanted to see the Planets. Imagine if we are able to capture a distant deep sky objects many light years away onto our PC screens or any screen for that matter?  Moon is taken for granted but how many would have looked deep enough to see its numerous craters?

As with any hobby, there are certain considerations ( not caveats ) and astronomy has many of them. For eg:-

·         Cost

·         Weight constraints

·         Portability ( would naturally involve weight )

·         Volume ( you need to store your gear some place )

·         Usability ( depends on where you live and your work pattern )

·         Performance ( all parts in working condition for years )

·         Light pollution

·         Manual operation with ease

·         Both Manual and Automatic or go-to

·         Precision tracking

·         Alignment procedures

·         Polar alignment for astrophotography

·         All star alignment for visual with go-to

and many, many more. Fortunately, all above considerations are something  amateur astronomers would relish.  Accessible to them are equipment suitable for their needs. This is where the fun starts.

You live in a big city, light pollution, work pattern and a newcomer to this hobby,  the answer would suggest a Mount and Scope which allows tracking of objects automatically so that you spend more time viewing and less time star hopping or trying to find objects manually.

There are a huge variety of Mounts designed for automatic alignment and tracking in both Alt / Az and Equatorial formats.  Only a few user inputs are needed and your journey to catch each of the 110 Messier objects starts. Mind you, there are thousands of other objects that will keep you mesmerized for a lifetime.

Having had the taste of some of our Celestial neighbours,  especially Saturn  or Jupiter, even Lunar, the immediate thought that crosses our minds is to snap a picture and show off to our family and friends. Easier said than done.  That is not all. You then start catching what is known as in astronomy circles, “Aperture fever”.

Costs, portability, weight aside, ( even your health and age takes a backseat once you get aperture fever ), you yearn for that extra inch of space. To probe deeper, to see more details that may have once amazed you, to now stun the daylights out of you.  By this time, you have earned yourself a nice little niche in the list of amateur astronomers and gained relatively good experience exploring the heavens. Time to move on.

Choices aplenty the shopping cart or your neighbourhood telescope store suddenly becomes a very busy place.  For those married folks, the wife may also take a backseat for awhile but its all in good fun and good investment. At least that is what we try to tell our spouses.  We even allow for a bit more spending on their part, at least that’s what our wife’s tell us, in good fun of course.

Whereas the first yearning was for any scope and mount, you suddenly find yourself having a good stock of eyepieces, accessories, finderscopes and a couple of telescopes and mounts in the space of a very short time.  New designs that hit the market ever so often only make matters bett....err worse. But buy one must.

To me, buying any astronomical item that serves the purpose is better than spending on items that you most likely never use. On the good side, most of the astronomical gear have a very good re-sale value, even after years of use.

Having satiated your appetite with aperture, your next line of thinking is somewhere between becoming an amateur astrophotographer or a casual one. Almost everyone has a camera and for those who don’t, the Android phones have one.  All it takes is one look at Saturn and then trying to align your camera towards the eyepiece, focus and shoot. A blurred, out of focus or clear, stunning image may appear with which you show your family and friends and proudly share on social networking sites.  A lot of ‘likes’ and ‘wows’ later, you suddenly become serious.

Note:  The technology available today was not available perhaps ten years back and Astronomy is considered the second most popular profession. Therefore it is fair to assume most of the amateur astronomers are ‘visual viewers’ and not astrophotographers and continue to be so even to this day.  There is a certain charm in star hopping or viewing an object for hours on end. Come back the next night and view the same object and you may see more details emerge. You train your eyes and observing skills as you experience the skies.

Astrophotography can be rewarding and how much you spend in terms of both money and time, would depend entirely on your own self analysis of what you wish to achieve.

Again with today’s advancement in technology, a plethora of options are available for beginners, intermediates who intend to embark on this very fulfilling journey in astro imaging. I have not mentioned the word ‘professional’ as this category of imagers would most likely have their own blogs or websites and would have written books on astrophotography. I know a few who actively share their spectacular images on various websites and my hats off to them.

While many are satisfied by simply using their point and shoot cameras or android phones to snap a image or two of brighter objects like our Moon or Saturn, quite a few go a step further and try their hand in longer exposures, i.e., anywhere from 15 secs to 24 hours.  Okay now 24 hours may sound a bit too much but it has been done over a span of several nights. Auto guiding, specialized guiding software like PHD etc., help keep a scope and camera pointed at the selected object while dedicated software like Backyard EOS for example lets you compute the duration and number of exposures you intend to take.  All this means you can set everything up and go back to watch TV or stay up and use your other scope for visual viewing.

Which category one intends to fall into is something only the user can resolve.   This could be through trial and error or if fortunate enough, suggestion and use of your friends imaging gear. The latter is wishful thinking though.  But today’s technology offers us so many good choices, it is rather difficult to make a serious error. The most sought after design for Astrophotography is the “Equatorial Mount” and there are plenty to choose from. Both from heavy to medium to lightweight.

Then there are Alt / Az mounts which allow the user to take up to 30 seconds without stars trailing or perhaps even more by installing a ‘wedge’.

Then you have an altogether a completely new concept developed which lets you mount your camera and image the night skies.  This small and lightweight instrument is made by various brands but the one I own is iOptron’s Skytracker. ( You can read various reviews on the web as well as on www.indianastronomer.net )   

There are portable versions of Equatorial mounts such as iOptron’s SmartEQ and even the ZEQ25GT.  You want to go up a tier then perhaps the iEQ30 or iEQ45. But for beginning and intermediate needs, the ZEQ25GT should prove adequate.

There are plenty other options as well but I am listing what I have seen and from my own experience.

The other important aspect to astrophotography is the choice of scope. Nothing less than  a Pandora’s box this.  On one hand you want to both view and image, on the other, you want the best imaging scope.  There are in-betweens fortunately so choose wisely.  Only be careful on the focal length and design.  A longer focal length may give you very good views on the Planets and other brighter objects but will induce star streaks whilst imaging deep space objects.  A short focal length and fast focal ratio would mean faster exposure times and wide field images of deep sky objects.   A large aperture scope would mean tons of light gathering prowess which would equate to much pleasing details but at the cost of volume and weight.  Lots of considerations.

Many astrophotographers settle on a nice little Doublet or ED or a Triplet, simply because these Refractors do not require much cool down times or collimation as well as being portable. Their lightweight makes them easier to mount on Mounts which have stipulated payloads so that a guide scope can be added atop or in future as you learn the art.

Some settle with an Achromat refractor as long as they do not mind the purple fringing or halos around the stars and brighter objects. As I said earlier, the answer lies with the user.

Some live with the Schmidt-Cassegrain design as this allows for better visuals and detailed images of the Planets.  However their long focal length and focal ratio would mean you need to use a ‘Focal Reducer’.  The Focal reducer acts in reducing the Focal ratio of an F/10 to an F/6.3, thus enabling  faster exposure times.

Finally you have to decide on the type of Camera you wish to image with. A DSLR is quite versatile and there are dedicated astro imagers too.  For DSLR owners, modding can be performed at a cost or through dedicated filters. One filter which really works well in light polluted cities is the CLS II clip-in filter. 

Processing software and free at that like Deep sky stacker, Registax, AutoStakkert, Gimp2 are available for the user to download and use. It helps if after spending all that money on astronomical equipment, to get yourself a dedicated astro processing software.  There are many available, even for those who are not technically savvy at processing.  These are programs that compute tons of information by the mere click of a few icons.

Personally I find the Deep sky stacker and AutoStakkert to be of great value in helping stacking images, while Photoshop Elements and PaintshopPro together with Noel Carboni’s tools provide enough processing power to bring out details in my images. I consider myself at the very least, a beginner when it comes to astrophotography but I pride myself in the knowledge that I have captured loads of images which my family and friends like. 

More importantly, I know my limits and therein lies the answer. The equipment which I own perhaps justify these limits and my work pattern, location, cost and other considerations.

Today the modern astronomer has the technology at their disposal to start almost instantly. The options are on par with the considerations.  All you need to do is choose wisely.  This is one hobby where the equipment lasts for a lifetime but the time available in our hand to look up each and every object in the sky may well take over a lifetime.

Haseeb Modi.

Please visit www.indianastronomer.net to help spread astronomy in India.